Echocardiographic Findings in Children with Tetralogy of Fallot

Original Article

Echocardiographic findings in children with Tetralogy of Fallot

Urmila Shakya, Poonam Sharma, Manish Shrestha

Department of Pediadtric Cardiology, Shahid Gangalal National Heart Centre Bansbari Kathmandu, Nepal Correspoding Author: Poonam Sharma, Department of Pediadtric Cardiology, Shahid Gangalal National Heart Centre Bansbari Kathmandu, Nepal, Email: [email protected]

Abstract Background and Aims: Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease in children. The aim of this study was to identify various cardiac defects associated with TOF by transthoracic echocardiography. Methods: All children presenting to Shahid Gangalal National Heart Centre, with the diagnosis of TOF from 2014 to 2015 were included in the study. Echocardiograpic reports of all eighty eight children were reviewed. Results: The mean age of presentation was 3.5 ± 3.9 years. Fifty six (64%) children were male and thirty two (36%) were female. Pulmonary artery anomaly was found in nine (10.2%) children which included hypoplastic pulmonary arteries, absent left pulmonary artery, post stenotic and aneurysmal dilatation of pulmonary artery. Pulmonary valve anomalies were seen in 13(14.8%) children which include pulmonary atresia, pin-hole opening of valve and bicuspid and absent pulmonary valve. Double outlet right ventricle, patent ductus arteriosus/major aortico-pulmonary collaterals, atrial septal defect and persistent left superior venacava were present in 12 (13.6%), 21 (23.9%), 22 (22.7%) and nine (10.2%) respectively. Right sided aortic arch was seen in 20 (22.7%). Conclusion: TOF is associated with various anatomical variations which need to be identified to avoid surgical complications. These can be diagnosed by echocardiography which has greatly reduced the need for invasive cardiac catheterization for these patients.

Key words: children, echocardiography, Tetralogy of Fallot

Introduction: Centre for one year from 14th April 2014 to 13th April Tetralogy of Fallot (TOF) is the most common cyanotic 2015. The echocardiographic findings of all children congenital heart disease in infants and children accounting with the diagnosis of TOF or TOF physiology were 1 for 3.5% of all congenital heart disease. The clinical reviewed. The study was approved by the ethical features of TOF depend on the severity of right ventricular committee of Instituitional Review Board of National outflow tract (RVOT) obstruction. Some children with Heart Centre. Informed consent was taken from the minimal RVOT obstruction have history similar to parents/guardians. ventricular septal defect (VSD) without cyanosis whereas The data was evaluated by SPSS Statistics 20. those with pulmonary atresia have marked cyanosis with Variables such as age and gender were presented as simple greatly reduced pulmonary blood flow which may be descriptive statistics. Mean and standard deviation of entirely dependent on patent ductus arteriosus (PDA). numeric data and frequency/percentage of qualitative data The symptom of TOF is also dependent on the site of was calculated. Outcome variables such as associated lesion obstruction of RVOT. Children with infundibular stenosis and anatomic variations were calculated in percentage. have a more dramatic dynamic spasm presenting as classic hypercyanotic spell.2 Many associations were described with this Results: common cyanotic heart disease in the literature. However till date no study has been conducted in such children A total of 88 patients were diagnosed with TOF within in Nepal. Hence this study has been conducted to note the study period of one year. Children from birth till 15 the common features and association among Nepalese years were evaluated.Among the study population, 56 children suffering from TOF. (63.6%) children were male and 32 (36.4%) were female. The mean age of presentation was 3.5± 3.9 years. Majority of children were less than one year of age including 39 Methods: (44.4%) children followed by age between 1 to 5 year It was a single centre retrospective observational of age which were 29 (32.3%) children. Only 9 (9.4%) study conducted in Shahid Gangalal National Heart children were older than 10 years.

Table 1: Age distribution Table 3: Abnormalities of Pulmonary valve and Pulmonary artery Frequency Number of children Percentage Pulmonary Artery Anomaly Pulmonary Valve Anomaly < 1 month 7 8.0 No Pulmonary No Abnormality (Percent) Atresia (Percent) < 1 year 32 36.4 Hypoplastic 1-5 years 29 33.0 Pulmonary 4 (4.5%) Pulmonary Atresia 8 (9%) Artery 5-10 years 11 12.5 Absence of Pin hole opening 1 (1.1%) 4 (4.5%) >10 years 9 10.2 LPA of PA Post stenotic Bicuspid dilatation of 3 (3.4%) 1 (1.1%) pulmonary valve PA All the children had levocardia except for two cases, one Aneurysmal with situs inversus with dextrocardia and the other with Absent pulmonary dilatation of 1 (1.1%) 1 (1.1%) mesocardia. Pulmonary artery anomaly was present in valve RPA and LPA nine (10.2%) children. Hypoplastic and small pulmonary arteries was seen in four patients and one child had absence of left pulmonary artery. Post stenotic dilatation The frequency of the site of pulmonary stenosis is shown was seen in three children and another child with stenotic in Table 4. The most common type of pulmonary stenosis pulmonary valve had aneurysmal dilatation of right and was combination of infundibular and valvular stenosis left pulmonary artery. occuring in 57 (64.8%) of children with isolated valvular Abnormalities of pulmonary valve were seen and combination of supravalvular and valvular stenosis in 13 (14.8%) children. Among them pulmonary atresia being the least common. was present in eight (9.1%) and small pinhole opening of pulmonary valve was present in four (4.5%) children. Pulmonary valve was bicuspid in one and absent in another Table 4: Site of Obstruction in Right Ventricular Outflow Tract child. Double outlet right ventricle (DORV) defined by Site of obstruction Number of children Percentage absence of mitral aortic fibrous continuity or overriding of aorta > 50%, was present in 12 (13.6%) children. PDA or Infundibular 5 5.7 MAPCAs were present in 21 (23.9%), ASD in 20 (22.7%) Valvular 1 1.1 and persistence of left superior venacava was present in 9 Infundibular and (10.2%) children. Similarly right sided aortic arch (RAA) 57 64.8 Valvular was seen in 20 (22.7%) children. Supravalvular and 1 1.1 Valvular Table 2: Associated Abnormalities in TOF patients Infundibular, Valvular and 24 27.3 Number of Percentage Abnormality Supravalvular children of children

Pulmonary artery anomalies 9 10.2% Discussion: Pulmonary valve a bnormalities 13 14.8% TOF is the most common cyanotic congenital heart disease in children beyond the neonatal period seen PDA/MAPCAs 21 23.9% in 3.5% of all infants with congenital heart disease with an incidence of 0.28/1000 live births.3 Although ASD 20 22.7% first identified by Niels Stenson in 1671, the precise anatomical description was given by William Hunter PLSVC 9 10.2% in 1784 as a communication between two ventricles with obstruction to the pulmonary artery flow.4 The DORV 12 13.6% anatomical defect, its pathological features and the clinical implications were later described by Louis Arthur 5 Right sided aortic arch 20 22.7% Fallot in 1888 as ‘cyanose cardiaque’ (cardiac cyanosis). It was however a Canadian Pediatric Cardiologist Maude

Abbott in 1924 who coined the term Tetralogy of Fallot child with situs inversus. (tetrad of VSD, right ventricular outflow obstruction, The most common site of obstruction in over riding of aorta and right ventricular hypertrophy).2 our study was a combination of infundibular and Nowadays we consider TOF to be a family of diseases valvular stenosis which was present in 65% of children. with similar intra cardiac anatomy but with variability of Infundibular stenosis was present in 97.8%, valvular in pulmonary artery anatomy, other associated anomalies 94.3% and supravalvular in 28.8% of children. Agrawal et and outcomes. al in India have noted subvalvular stenosis to be present in Although TOF is said to have an equal gender 96.1%, valvular in 83.9% and supravalvular in 33.3% of prevalence,2,6 our study revealed it to be more common in children.13 males (65:35). Similar finding was noted by studies done in Despite all these associated abnormalities, Iran and Pakistan. , The mean age of children in our study our study lacked to show coronary artery abnormalities group was 3.5 ± 3.9 years with most cases (44%) being less found not infrequently in patient with TOF. Some of the than one year of age. This is comparable to a study done coronary information may be crucial for the definitive in Turkey where children presented at an age of 3.9 ± 2.9 repair. Certainly this is one of the limitations of our study. years. However studies in Pakistan have reported delayed Further, the study has limitations of being single centre presentation.8 and retrospective design. Various authors have mentioned about different anomalies associated with TOF. Most of these associations have been identified by cardiac catheterization. We have Conclusion: however studied the association identified by transthoracic TOF is the most common cyanotic congenital heart echocardiography without any invasive procedures disease encountered in a cardiac clinic and has many and our findings are comparable to those identified by associations. Although in the past cardiac catheterization catheterization. Pulmonary artery anomaly was found in was necessary in all the children with TOF to identify 10.2% of TOF children in our study, which was similar the exact anatomy and known variation, improvement in to Farsani et al.7 This is however slightly lower than that transthoracic echocardiography has significantly reduced noticed by Sheikh et al where pulmonary artery anomaly was seen in 19% of children with TOF.10 This could be the necessity of these invasive procedures in children. because Sheikh et al have included supra valvular stenosis as a pulmonary artery anomaly. References Pulmonary Atresia is one of the known anatomic variant of TOF which is present in 5-10% of all TOF 1 Linde D, KoningsEEM, SlagerMA, et al.Birth cases.11 Our study also revealed pulmonary atresia to Prevalence of Congenital Heart Disease: be the most common valve abnormality seen in 9% of Worldwide A Systematic Review and Meta- children with TOF. Analysis. JACC 2011;58: 2242-7. PDA/MAPCA was the most common 2 Bonchek LI, Starr A,Sunderland CO, et al. Natural abnormality in our study which was present in 24% of History of Tetralogy of Fallot in Infancy Clinical children followed by ASD present in 22%. The percentage Classification and Therapeutic Implications. of PDA/MAPCA could be high in our study because we Circulation 1973;48: 392-7. have also included TOF with Pulmonary Atresia where 3 Apitz C, Webb GD, Redington AN. Tetralogy of the pulmonary circulation is entirely dependent on PDA. Fallot. The Lancet 2009;374: 1462-71. Similar finding was noted in Pakistan where PDA and 4 Praagh RV. The First Stella Van Praagh Memorial MAPCAs were present in 20% of children.9 Although Lecture: The History and Anatomy of Tetralogy right sided aortic arch is of little clinical significance, it is of Fallot. Pediatric Cardiology Surgical Annual one of the frequent anomalies seen in TOF and needs to 2009;12:19-38. be correctly notified to the surgeons prior to the surgery 5 Swamy P, Bharadwaj A,Varadarajan P, et al. Echo in to avoid complications. In our study RAA was present in adult congenital heart disease; Echocardiographic 22% of children. Similar finding was seen in Iran where Evaluation of Tetralogy of Fallot. Echocardiography it was seen in 21% of children.7 Saeed et al noted a much 2015;32:S148–S156. lower incidence of RAA in TOF patients.8 6 Bailliard F, Anderson RH.Tetralogy of Fallot. TOF is known to be associated with double Orphanet Journal of Rare Diseases 2009;4: 1-10. outlet right ventricle. 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9 Kervancioglu M, Tokel K, Varan B, et al. Frequency, and pulmonary atresia with major aortopulmonary origins and courses of anomalous coronary arteries collateral arteries and septic embolism.Acta in 607 Turkish children with tetralogy of Fallot. Radiologica Short Reports 20014;3: 1-4. Cardiology Journal 2011;18: 546-51. 12 DiLorenzo M, Weinstein S, Shenoy R. Tetralogy 10 Sheikh AM, KazmI U, Syed NH, et al. Variations of Fallot with Dextrocardia and Situs Inversus in a of pulmonary arteries and other associated 7-Year-Old Boy. Tex Heart Inst J 2013;40:481-3. defects in Tetralogy of Fallot. SpringerPlus 13 Agrawal S, Soni D, Dhawan S, et al. Sites of right 2014;3:467-70. ventricular outflow tract obstruction in tetralogy 11 Dobrocky T, Klink T, Weisstanner C, et al. of Fallot--a retrospective study. Indian Heart J Imaging findings in uncorrected tetralogy of Fallot 1991;43:455-9.

Cite this article as: Urmila Shakya, Poonam Sharma, Manish Shrestha. Echocardiographic findings in children with Tetralogy of Fallot. Nepalese Heart Journal 2015;12(2):65-68.